Search found 406 matches

by l_oliveira
Tue Dec 15, 2020 9:43 am
Forum: NES Hardware and Flash Equipment
Topic: Weird thing happened after washing a NES clone PCB
Replies: 25
Views: 7979

Re: Weird thing happened after washing a NES clone PCB

Fisher wrote:
Mon Dec 14, 2020 4:23 am
Strangely on my cce copy of Gradius even if I remove the buffer ICs the control acts as if all the buttons are pressed, resulting on the gray test screen.
This is the expected behavior because 368 is an inverting buffer.
by l_oliveira
Sun Dec 13, 2020 3:44 pm
Forum: NES Hardware and Flash Equipment
Topic: Weird thing happened after washing a NES clone PCB
Replies: 25
Views: 7979

Re: Weird thing happened after washing a NES clone PCB

Maybe the buffer ICs are damaged now? 74HC368
by l_oliveira
Thu Dec 10, 2020 7:50 pm
Forum: NES Hardware and Flash Equipment
Topic: Weird thing happened after washing a NES clone PCB
Replies: 25
Views: 7979

Re: Weird thing happened after washing a NES clone PCB

Phantom System is a crap system. Why? Because who designed it took the game controller i/o control strobes (which come from the 2A03) and shoved them along with the audio and video output from the CPU and PPU on the middle unused pins of the cartridge connector. Whatever Gradiente did put their han...
by l_oliveira
Tue Dec 03, 2019 10:22 pm
Forum: NES Hardware and Flash Equipment
Topic: SNES video problem
Replies: 16
Views: 6546

Re: SNES video problem

On the case of MC1377 it autodetects the video mode and operates on PAL encoding if it detects 50Hz video. It has a override pin which allows you to force it to always stay on NTSC mode. Tec toy used a similar circuit to inject the color burst signal on the ntsc override pin causing the MC1377 to en...
by l_oliveira
Mon Dec 02, 2019 9:04 pm
Forum: NES Hardware and Flash Equipment
Topic: SNES video problem
Replies: 16
Views: 6546

Re: SNES video problem

BA6592 does not support output PAL color encoding under 60hz vsync and that hack solves the issue. S-ENC doesn't need that, works correctly on PAL-M. Tec Toy did something similar on their first SMS model on a MC1377 encoder, they do that to cause the internal counter at the encoder to reset at a di...
by l_oliveira
Fri Jul 26, 2019 12:34 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

This is what the 74LS32 is doing on that cart (might not be wired physically like this on my cart as I just drew this from my head). The circuit below is meant to make up to the fact that 62256s have no non-inverted Chip Enable pin. VRC6_32KWRAM.PNG The second OR gate is useless, isn't it? Connect ...
by l_oliveira
Sun Jul 21, 2019 8:43 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

What you do with the /WE signal of the FRAM? connect straight to R/W?
Connected like this, right?
CE# = /WRAM_CE coming from mapper logic.
OE# = GND?
WE# = R/W?
by l_oliveira
Sun Jul 21, 2019 6:50 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

Now I understand how to use 74'32. Why not power 74'32 with +5V, and pull 62256's /CE to +3V of battery through a big res(e.g. 100k)? This eliminates the power consumption of 74'32 when cart is not working. The purpose of the MN1026 IC is control the SRAM power consumption from the battery and make...
by l_oliveira
Sun Jul 21, 2019 6:47 am
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

Just don't forget to supply 7432 from the battery aswell and use CMOS variant (74HC/74HCT), not the TTL (LS/F) What I did with the normal 74LS32 defeats the need of using special low power logic and reduces consumption from the battery. the MN1026 has inverted and non inverted outputs. Edit: Just t...
by l_oliveira
Sat Jul 20, 2019 9:14 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

Oh it just occurred me that FRAM may actually require /OE and /WE to pulse for it to pass through the rewrite cycles from read and write accesses. I suggest Haruka try this circuit with the 74LS32 I posted on the previous post for creating specific /OE and /WE signals for the FRAM while having the F...
by l_oliveira
Sat Jul 20, 2019 8:58 pm
Forum: NES Hardware and Flash Equipment
Topic: VRC-VI multicart
Replies: 39
Views: 29276

Re: VRC-VI multicart

This is what the 74LS32 is doing on that cart (might not be wired physically like this on my cart as I just drew this from my head). The circuit below is meant to make up to the fact that 62256s have no non-inverted Chip Enable pin. VRC6_32KWRAM.PNG Maybe it could be simpler with your FRAM IC, you m...
by l_oliveira
Sat Feb 23, 2019 7:36 pm
Forum: NES Hardware and Flash Equipment
Topic: FME-7 and SUNSOFT 5B are different?
Replies: 54
Views: 54528

Re: FME-7 and SUNSOFT 5B are different?

I've just do a Gimmick Repro out of Barcode World (FME-7), without desoldering SRAM chip (gimmick banks PRG-ROM at $6000-$7fff) http://bootgod.dyndns.org:7777/profile.php?id=1543 and it works without problems so saying that FME7 cannot bank ROM at $6000-$7fff is not true. BTW. I am having this cart...
by l_oliveira
Sat Oct 21, 2017 3:54 pm
Forum: NES Hardware and Flash Equipment
Topic: Help fix a NES Clone (Phantom System)
Replies: 135
Views: 57719

Re: Help fix a NES Clone (Phantom System)

You should be testing for broken traces maybe.

Also have you tested a different CPU IC on that system?
by l_oliveira
Thu Oct 19, 2017 6:16 pm
Forum: NES Hardware and Flash Equipment
Topic: Help fix a NES Clone (Phantom System)
Replies: 135
Views: 57719

Re: Help fix a NES Clone (Phantom System)

Phantom System has some silly crap on it's design like some control lines of the CPU connected to the cart slot which aren't supposed to... Audio and Video on the cart slot? Only to make the signals gather interference from the bus signals, right? Why a cartridge would need/want INP0/INP1 pins or OU...
by l_oliveira
Wed Oct 18, 2017 5:30 am
Forum: NES Hardware and Flash Equipment
Topic: Why my famiclone have space to two xtal?.
Replies: 46
Views: 21196

Re: Why my famiclone have space to two xtal?.

Intestingly, the console that has no glitch has an AHCT latch, while the other has an LS. I think this may comprove the low voltage theory, aren't the AHCT more tolerant to these kind of voltage differences?? That happens with the powerpak too. People replace the PPU latch IC to attain better power...